Fastener



Dec. 5, 1950 o. J. HUELSTER `2,533,115

FASTENER Drignal Filed Aug. '7, 1943 INVENTOR. @my a/4m EM .f/@aww ATTORNEY Patented Dec. 5, 1950 Z,533,ll5

FASTENER Otto J. Huelster, Waterbury, Conn., assignor to Scovill Manufacturing Company, Waterbury, Conn., a corporation of Connecticut Original application August 7, 1943, Serial No. 497,721, now Patent No. 2,486,412, dated November 1, 1949.

Divided and this application September 18, 1945, Serial No. 617,010

7 Claims.

rihis invention relates to fasteners, and more particularly to fasteners of the cam and stud type, one use of which is in aircraft for detachably securing such parte as cowlings, covers, and hoods to mounting structures. is a division of my co-pending application Serial No. 497,721, now Patent No. 2,486,412, issued November 1, 1949.

In general, such fasteners have two elements,

one of which, a cam faced member, is fixedly= attached to one part, and the other of which, a stud having a cross pin adapted to ride the cams into locking position, is attached rotatably to the other part. The studs are manufactured and kept in stock in various lengths to enable the fasteners to be used with parts of various thickness, but it is not infrequently the case that the correct size is out of stock or that a wrong size is chosen, resulting in waste of the time required to obtain a correct size, or in the assembly of:

into engagement with the cam, and if the parts .I

to be fastened are curved, the difficulty is increased.

One of the objects of the present invention is to provide a novel cam and stud fastener having a stud of adjustable length adapted to fit parts of various thickness.

Another object of the invention is to provide a novel fastener which is so constructed that the laterally projecting elements of the stud, commonly referred to as the cross pin, may be moved relative to the head of the stud after assembly, so as to increase or decrease the effective length thereof and adapt the fastener to parts or plates of various thicknesses.

Another object is to provide a novel fastener which may be quickly engaged or released, even when the parts to be clamped or unclamped are not in exact alignment, and a particular object is to construct the cam element of the fastener with lateral adjustability suflicient to compensate .1

for ordinary types of misalignment of parts.

rhe above and further objects and novel features of the invention will more fully appear from the following detailed description when the same is read in connection with the accompanying Si,

This application 1,5

drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a definition of the limits of the invention, reference for this latter purpose being had primarily to the appended claims.

In the drawings, wherein like numerals refer to like parts throughout the several views,

Fig. l is a sectional view, taken substantially on the line iv-i of Fig. 2, of a fastening' device embodying the present invention;

Fig. 2 is a plan view of the fastener in use;

Fig. 3 is a horizontal section taken on the line 3 3 of Fig. 1; Y 4

Fig. 4 is a plan view of the cam block shown in Fig. l;

Fig. 5 is a section on line 5 5 of Fig. 4; and

Fig. 6 is an enlarged showing of the stud and the` elements carried thereby, the View being taken substantially on the line i--l of Fig. 2.

The present invention is illustrated, for eX- ample, in connection with a Cowling plate and the frame of an airplane, portions of the plate and frame being indicated at il) and Il, respectively, which are supposed to be axially in alignment with each other when said plate and frame are in assembled relation, but the opening i3 is larger in diameter than the opening i2, and the parts frequently become offset to such an extent that ordinary fasteners are not satisfactory.

Secured to the inner surface of frame i l as, for example, by rivets I4, and enclosing the opening i3 in said frame, is a socket indicated generally at I5 (Fig. 1). This socket l5 is formed by an inner, thin metal, cup-like shell i6 provided with a laterally extending iiange Il.' and an outer, thin metal, cup-like shell it provided with a laterally extending flange I9. The shells or plate-like supporting members i5 and I8 are of such construction that when said shells are nested to form the socket i5, space 2i) (Fig. l) is provided between the outer and inner shells I8 and i5, and the inner shell is offset and spaced from the plate l l as indicated at 2|.

Disposed in the spaced mid-portions of space 2i! between the shells l t and I8 is the circular iiange 22a of a cam block Z2 which is provided on the lower side (as viewed in Fig. 1) with a square pad or flange 23, and on the upper with a circular iiange or boss 24 (Fig. 1, 4 and 5). Flange 23 projects loosely into a square opening 25 formed in the inner shell It, and boss 24 projects into a circular opening 25 formed in the outer shell I3 (Figs. l and 2). After the cam block is positioned between shells i5 and |8,.the latter are secured that of opening i3 in plate il.

together, preferably by spot welding to simplify handling thereof, but it will be understood that the shells may be secured together in any other suitable manner known in the art. The Cam block 22 is held against rotation by square flange 23 but is adapted to slide or fioat in the space 2d in any direction parallel with the face of frame H until its motion is arrested by the Contact of square ange 23 with the square opening 25 in shell It.

Referring to Figs. 4 and 5 of the drawing, the oating Cam block 22 is provided with a central opening 2l', which is disposed in axial alignment with the opening i3 in the frame il, with two diametrically opposite slots 28, and on the top side thereof and on opposite sides of slots 28 with a pair of diametrically opposite cani surfaces 23 which are inclined upwardly from said slots, are

, continued as diametrically opposite recesses 3d,

and terminate in abutments 3l formed by extensions ,i on said cam block which prevent the pin of the stud vfrom being rotated beyond locking position in the recesses.

With the construction thus far described, it will Toe noted that the socket l5 and oatine cam block 22 carried thereby constitute the car-5: asseznblyof the fastener fixed to the frame of the airplane. The stud assembly of the fastening device, which cooperates with the floating 'earn block 22 for yieldingly clamping the detachable cowling plate It to frame li, is carried by plate it and is constructed, mounted, and operated as follows:

Extending loosely through the drifted open'- ing i2 in Cowling plate lil is a thin metal, springl retainer or cup member 33 with an outwardl;` depending skirt 3d that is inclined or tapered in conformity with the contour of the drifted hole for direct engagement with the Cowling plate.

The spring retainer 33 is provided at its top oi" inner end with a central opening 35, and ade jacent said end with an outwardly projecting annular bead 35 which is smaller in diameter than the opening i2 in the Cowling plate It so that the retainer may easily be applied to said plate and quickly removed therefrom. Retainer t is held against displacement from cowlin-g' plate it by a split ring 3l which is engaged overl said retainer between the annular bead 36 there of and said Cowling plate, and when so engaged is expanded to a diameter larger than the diameter of bead S5 and opening I2, but less than The retainer is preferably made of a wear resisting metal, such L steel, and its use avoids the necessity for the usual eyelet to protect the surface of plate i" adjacent opening I2.

Loosely carried by retainer 33 and projecting through the opening 35 therein is a stud 3B l) provided on its lower or outer end with an enlarged head 39 which is beveled, as at (it, to provide sufficient clearance between said head and the inner surface of the skirt 34. Stud 38 has formed therein a central opening lll which is counterbored at its opposite ends to provide a shallow pocket i2 and a shoulder d3 at the bottom or cuter end thereof, and with a deep pocket 'di at the top or inner end thereof. The stud is further provided with two diametricall;J opposite slots d5 traversing the pocket M and extending the full length of said pocket. The head S9 of the stud 38 is slotted as indicated di? to receive a screw driver` or other suitable tool for rotating the stud. Surrounding stud 33 and interposed between the stud head 39 and retainer 33 is a compression spring 4l for yieldably hold- Vor outer end with an enlarged slotted head ing said retainer against Cowling plate lil, and for yieldably applying clamping pressure to said stud. The spring retainer 33 and spring il extend into the space 2i provided by offsetting the central portions of the inner and outer shells away from their attaching portions.

Fitted for sliding movement within and along the pocket dit in the stud 38 is an internallyl tareaded, cylindrical nut or sleeve t8 having secured thereto, or formed integrally therewith, two laterally extending pins d@ which project through the slots i5 in said stud. Sleeve i8 its pins constitute a cross-pin member. rThe distance between the outer ends of the cross pins dii is less than the diameter of the opening in the cowling plate lil, and slightly less than the distance between opposite ends of the slots in cam block 22 to permit said pins to freely pass through said opening and slots.

Arranged within the pocket id in the stad 58 is a screw 5t having threaded engagement with,

. sleeve 58. This screw 5? extends through oper ing di in stud 38 and is provided on its lotv which is disposed within the pocket l2 and abut; against the shoulder d3. Since sleeve et is heid inst rotation relative to the stud 33 by the engaged in slots d5, rotation of the screr; l v-fill cause the cross-pin member d8, 49 to move axially along the stud 33, increasing or decreasing the distance between said pins and the head 39 of said stud in accordance with the direction of rotation of the screw.

To prevent spreading or contracting oi the walls of the stud 3d surrounding the pocket d which would result in excess play or binding the nut or sleeve de in said pocket, the stud 33 has engaged therewith at its top or inner open end a friction bushing 52. This friction bushing 52 is provided on its lower end, as viewed in Fig. 6, with a reduced portion 53 which extends into the pocket lili, and with a beveled or tapered groove 5d that engages the corresponding beveled or tapered upper end 5ta of the stud 38.

The bushing 52 is connected with adjusting screw te for rotation therewith relative to stud 3S, and byreason of the frictional relationship at surfaces 5d, 5ta the bushing 52 will also rotate with stud 3S, screw 5G and cross-pin member 4i), i9 as a unit when said stud is rotated. As shown, screw Si@ is formed at its upper end with a reduced neck portion 55 which extends through a suitable openincr formed in bushing 52, and also through a suitable opening formed in a resilient bearing Cap 5t engaged with said bushing. The bearing cap 56 is held in engagement with bushing 52, and the latter is held in frictional contact with the stud Sii by anging or turning the end the reduced neck portion 55 over the bearing cap 5t, said neck portion 55 being bored out, as indicated at 5l, to provide a thin wall for this purpose. The frictional Contact of the bushing 52 with the end of stud 38 at surface 511 is sufcient to prevent any accidental relative rotation of stud 3S and adjusting screw 5U and, hence, any accidental rotation of nut 4S, 49 from a preposition on screw 50. Bearing Cap is preferably forced over the upper reduced end of bushing 52 by a drive t to obtain a non- VrotatableV Connection between said cap 56 and bushing 52. It will be noted that frictional rota on can take place between beveled surfaces t 5de which serve the double function of prothe stud 38 issplit `for a major portion of its length by slots 45, holding the upper split ends of said stud (Fig. 6) against lateral spreading movement.

The s ocket I5 with the floating cam block 2 having been secured to the frame Il, and thel spring retainer 33, spring 41, and stud 38 with the adjustable cross pins 49 having been attached` to the cowling I0, as hereinbefore described, said cowling is now in readiness to be yieldingly and detachably clamped to said frame, as follows: Assuming that the cross pin member 48, 49 has been properly positioned along the stud 38 in accordance with `the thickness of plate I8 and fram.r II, the stud 38 is inserted into the opening 21 ir the cam block 22 and rotated as a unit in either direction until the cross pins 49 are in line with and pass through the slots 28 in said cam block. Preferably cross pin member 48, 49 is passed through opening 21 and slots 28 in cam block 22 by rotating stud 38 in a counterclockwise direc tion as viewed in Figs. 2 and 4. Pins 49 will be thus rotated against the underside of cams 29, 39, BI, which directly below the extensions 32 as viewed in Figs.4 and 5, are preferably rounded as at 58 (Fig. 5) whereby pins 49, moving along said surfaces 58, freely enter slots 28 in a plane above the underside of the cam surfaces opposite the portions designated by the reference character 29. Thus any effort to move pins 49 past slots 28 in a counterclockwise direction, as viewed in Figs. 2 and 4, causes said pins to4 engage the diametrically opposite ends of cams 29, 38, 3| so that the user knows that his pins 49 are now i alignment with the slots and he readily passes l stud with the cross pin member 48, 49 through opening 21 and slots 28. Stud 38 is then rotated by a screw driver, or other suitable tool, caus ing the cross pins 49 to ride up and along the cam surfaces 29 against the tension of the compression spring 41, and snap into the recesses and into engagement Withthe abutments 3 I. The Cowling I9 will thus be yieldingly but firmly 'clamped against frame I I, and the stud 38 dus to engagement of the cross pins 49 in the recesses 30 will be held against accidental rotary movement.

If the openings I2 and I3 in the cowling plate I8 and frame I I are not in proper alignment, the stud 88 upon rst entering the opening 21 in the cam block 22 will cause said cam block to float or move to a position, within prescribed limits.

where the opening 21 thereof is in axial alignment or substantially so with said stud, thus enabling the stud 38 and cross pins 49 to enter anr pass through the opening 21 and slots 28, respecY tively, in the cam block 22.

Should it be desired to positively lock the stud 38 against movement after the cowling I9 i clamped in position, this can be accomplished by rotating adjusting screw 58 with the aid of a screw driver, or other suitable tool, in a direction to cause the head 39 of the stud to move toward` the cross pins 49, compressing the spring 41 to such an extent that the further compressibility of the spring is less than the distance between the bottom of the recesses 39 and the high points of portions 29 of the cam surfaces.

rlhe stud 38 can be removed from the Cowling I9 for repair or replacement by retracting sleeve 48 through the rotation of screw 59, disengaging pins 49 through the rotation of stud 38, removing 'plate I and removing ring 31, whereupon retainer 33, spring 41, and stud 38 may be removed from. the Cowling as a single unit.

It will thus be seen that due to the adjustvability of the cross pins 49 along the studi 38, a `fastening device is provided which will accommodate all thicknesses of plates within the range of adjustment of said cross pins, and while the stud 38 with the adjustable cross pins 49 is herein illustrated and described in cooperation with a floating cam block 22, said stud and adjustable cross pins are equally adaptable for use with a fastening device wherein the cam or cam block is secured to or forms an integral part of the socket.

Due to the provision of the floating cam block 22, irregularities within prescribed limits in the alignment of the plate openings are automatically compensated for, and while said type of cam block is herein illustrated and described in association with adjustable cross pins, it is equally adaptable for use in association with a cross pin or cross pins that are secured to or form an integral part of the stud It is, therefore, to be expressly understood that while one embodiment of the present invention is herein illustrated and described with more or less particularity, said invention is not limited to said lembodiment or otherwise than by the terms'of the appended claims.

What is claimed is: i

l. In a fastener of the cam and stud type, a cam block, a boss projecting from said block, a polygonal ange projecting from the surface of the block opposite the boss, nested shells having offset, spaced mid-portions adapted to receive the said cam block, the outer of said shells having an opening adapted to adjustably receive said boss, the inner of said shells having a polygonal opening adapted to receive said polygonal flange and of such size and shape that adjustment of the block within the spaced portions of the shells is permitted but rotation thereof is prevented.

2. In a fastener of the cam and stud type, a cam block having a slot, a boss projecting from one face of said block, a rounded face formed near the end of said slot in the other face of said block adapted to guide a locking pin into the slot, a polygonal flange projecting from the opposite surface of the block, nested shells adapted to receive the said cam block having abutting rims adapted to be attached to a supporting member, the outer of said shells having an opening to adjustably receive said boss, and the inner of said shells having an opening to receive said polygonal flange of such size and shape that adjustment of the block within the spaced portions of the shells is permitted but rotation thereof is prevented.

3. In a fastener of the cam and stud stype, a cam block having aslot, an annular boss surrounding said slot, rounded faces formed at the ends and at opposite sides of said slot adapted to guide a locking pin into the slot, a substantially rectangular flange projecting from the block and surrounding the slot and the said rounded faces, nested shells having abutting rims adapt-ed to be attached to a plate and having offset, spaced mid-portions adapted to receive the said cam block, the outer of said shells having an opening adapted to receive the boss and to permit adjustment thereof, the inner of said shells having a substantially rectangular opening adapted to receive said rectangular flange and of such size that adjustment of the block` within the spaced portions of the shells is permitted but rotation thereof is prevented.

4. In a fastener of the cam and stud type, a cam block having an elongated slot, Van vannular boss surrounding said slot, rounded faces formed at opposite ends and at opposite sides of said slot adapted to guide a locking pin into the slot, a substantially rectangular iiange projecting from the block and surrounding the slot and the said rounded faces, Ynested shells having abutting rims adapted to be attached to a plate and. having offset, spaced mid-portions adapted to receive the said cam block, the outer of said shells having an opening adapted to receive said boss and to permit movement thereof in any direction, the inner of said shells having a substantially rectangular opening adapted to receive said rectangular ange and of such size that adjustment ofthe block Within the spaced portions of the shells is permitted but rotation thereof is prevented.

v5. In a fastener of the cam and stud type, a cam block having an elongated slot extending therethrough, an annular boss encircling the said slot, rounded faces formed at opposite ends and at opposite sides of said slot in the other surface of lsaid block adapted to guide the pins of a stud into the slot, a non-circular ange projecting from the said other surface Aof the block and surrounding the slot and the said rounded faces, and nested shells having abutting rims adapted to be attached to a plate and having offset, spaced mid-portions adapted to receive the said cam block, the outer of said shells having a circular opening of greater size than the said annular boss adapted to receive said boss, the inner of said shells having a non-circular opening adapted to receive said non-circular ange and of such greater size that adjustment of the block within the spaced portions of the shells is permitted but rotation thereof is prevented.

6. In a fastener of the cam and stud type, cam means having a flange, and inner and outer shells having attaching portions forsecuring the shells to a supporting member, said shells having central portions offset from the attaching portions and spaced from each other to provide for a cani space, and which central portions are provided with openings through Which portions of the cam means loosely extend with the ange slidably positioned in said space, one portion of the cam means being adapted to engage the Walls of one of said openings to prevent rotation of the cam means relative to the shells.

7. A 'locking device, comprising in combination with a cover plate, and a base plate, a latching member having inclined surfaces adapted to be pressed by -a locking bar in the course of its locking and unlocking movements, and having recesses adapted to receive said locking bar in its unlocked and locking positions, a locking frame enclosing said latching member, means engaging said locking frame and said base plate and rmly lconnecting said locking frame to said base plate, and a resilient disc located between said base plate and said latching member, and bearing on both, said disc being subjected to bending pressure in the course of said 'locking and unlocking movements.

oTTo J. HUELSTER.

REFERENCES CITED The following references are of record in the le of this patent:

.UNITED STATES PATENTS Number Name Date 2,238,865 Purinton Apr. 15, 1941 2,327,331 Pender Aug. 17, 1943 2,337,483 Marty Dec. 21, 1943 2,356,162 Johnson et al Aug. 22, 1944 2,372,496 Huelster Mar. 27, 1945 

